频繁出现“偏移量超出范围”消息，分区被消费者遗弃

Question

我们运行的是3节点Kafka 0.10.0.1集群。我们有一个消费者应用程序，它有一个连接到多个主题的消费者组。我们在消费者日志中看到了奇怪的行为。有了这些行

 Fetch offset 1109143 is out of range for partition email-4, resetting offset
 Fetch offset 952168 is out of range for partition email-7, resetting offset
 Fetch offset 945796 is out of range for partition email-5, resetting offset
 Fetch offset 950900 is out of range for partition email-0, resetting offset
 Fetch offset 953163 is out of range for partition email-3, resetting offset
 Fetch offset 1118389 is out of range for partition email-6, resetting offset
 Fetch offset 1112177 is out of range for partition email-2, resetting offset
 Fetch offset 1109539 is out of range for partition email-1, resetting offset

一段时间后，我们看到了这些日志

[2018-06-08 19:45:28] :: INFO  :: ConsumerCoordinator:333 - Revoking previously assigned partitions [sms-4, sms-3, sms-0, sms-2, sms-1] for group notifications-consumer
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator:381 - (Re-)joining group notifications-consumer
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: AbstractCoordinator$1:349 - Successfully joined group notifications-consumer with generation 3063
[2018-06-08 19:45:28] :: INFO  :: ConsumerCoordinator:225 - Setting newly assigned partitions [sms-8, sms-7, sms-9, sms-6, sms-5] for group notifications-consumer

我注意到我们的一个主题没有出现在设置新分配的分区的列表中。那么这个话题至少在8个小时内没有消费者的关注。只有当有人重新启动应用程序时，它才会从该主题开始使用。这里会出什么问题呢？

以下是使用者配置

auto.commit.interval.ms = 3000
auto.offset.reset = latest
bootstrap.servers = [x.x.x.x:9092, x.x.x.x:9092, x.x.x.x:9092]
check.crcs = true
client.id =
connections.max.idle.ms = 540000
enable.auto.commit = true
exclude.internal.topics = true
fetch.max.bytes = 52428800
fetch.max.wait.ms = 500
fetch.min.bytes = 1
group.id = otp-notifications-consumer
heartbeat.interval.ms = 3000
interceptor.classes = null
key.deserializer = class org.apache.kafka.common.serialization.StringDeserializer
max.partition.fetch.bytes = 1048576
max.poll.interval.ms = 300000
max.poll.records = 50
metadata.max.age.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.sample.window.ms = 30000
partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
receive.buffer.bytes = 65536
reconnect.backoff.ms = 50
request.timeout.ms = 305000
retry.backoff.ms = 100
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.mechanism = GSSAPI
security.protocol = SSL
send.buffer.bytes = 131072
session.timeout.ms = 300000
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
ssl.endpoint.identification.algorithm = null
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLS
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.location = /x/x/client.truststore.jks
ssl.truststore.password = [hidden]
ssl.truststore.type = JKS
value.deserializer = class org.apache.kafka.common.serialization.StringDeserializer

孤立的主题有10个分区，retention.ms=1800000，segment.ms=1800000。请帮帮忙。

Answer 1

您看到的offset of range消息通常表示消费者所处的偏移量已在代理上删除。一旦命中，消费者将使用auto.offset.reset重新开始消费。

使用retention.ms=1800000 (30分钟)，您只能在很短的时间内保存数据，因此如果您在几个小时后重启消费者，数据将会丢失。